Several methods for delivering cargo via parachute exist, and generally most involve a primary delivery vehicle, the cargo itself, and a parachute for the cargo. Conventional means of cargo delivery, such as where the primary delivery vehicle is an aircraft and the cargo and cargo parachute are ejected in flight, are effective in many applications, but not all. Hence, other means have been developed, and one technique exists where the primary delivery vehicle is a parachutist wearing a parachute and harness (i.e. the primary delivery vehicle), and cargo is tethered to the primary delivery vehicle via a bridle, to which a cargo parachute container containing a cargo parachute is attached. The bridle, cargo parachute container, cargo parachute, and cargo are known as the cargo bundle.
Using this technique of cargo delivery, cargo can remain tethered to the parachutist until both the cargo and the parachutist reach the ground, or the cargo can be released from the parachutist while both are still in flight, after which the cargo parachute deploys to safely deliver the cargo. Hence, release systems which release the cargo from the parachutist are known in the art. It is also known that parachute operations can occur in a variety of environments under a range of circumstances. Occasionally this results in highly dynamic conditions for the cargo and more importantly, for the primary delivery vehicle, which is often piloted by a human, or, in the case of a parachutist, is a human. In the case where the cargo bundle must be released and the release must be effected by a human, such as where the primary delivery vehicle is a parachutist wearing a tandem parachute harness, the release system must work even when highly dynamic conditions generate increased forces on the release system. Hence, release systems are known that release a parachute or cargo bundle even during dynamic conditions.
A current cargo bundle delivery system employs a parachutist's parachute harness, which also has multiple attachment points for a cargo bundle, known as a tandem parachute harness, the cargo bundle with multiple attachment points for attaching to the tandem parachute harness, and multiple connectors, one for each point of attachment, all of which is piloted by a parachutist.
The connectors in the existing system are three-ring release systems that are known in the art, where the double ring component of the three-ring release system connects to the tandem parachute harness attachment points, and the single ring component is incorporated into the bridle attachment points. A flexible cable is inserted into a release loop of the three-ring release system, which holds the single and double ring components together. When this cable is removed by sliding it axially from the release loop, the single and double ring components separate, and the connection is broken. A separate three-ring release system is used for each point of attachment between the tandem parachute harness and the bridle attachment points.
The manual disconnect system for the above described system contains a handle which is attached to a single cable. This single cable separates into four cables, and each cable is routed to respective attachment points, and serves as the cable that is inserted into the release loop of the three-ring release system. Hence, pulling the release handle will pull all four cables from their respective release loops, which will release the cargo bundle from the harness.
Releasable connectors require an amount of force to effect the release the releasable connector, i.e. a release force. To release the cargo in this human powered release system, the parachutist must generate enough force to overcome frictional forces present on the cable by the release loop and cable housings, generated by the force of the cargo. Hence, reducing friction on the cables is of paramount importance. Further, simultaneous release of the multiple points of attachment is important. Mismatched timing of release and the cargo bundle may not release at every attachment point, possibly changing the configuration of the cargo delivery system, and adding more unpredictability to the situation.
In response to these requirements, the release system of the prior art has used three-ring releases to connect the cargo bundle to the primary delivery vehicle, because they reduce the force that must be applied to the cable in order to release the bundle. The cables have been routed through cable housings which can be bent, but not crushed, in order to provide a low friction path for the cable, and smooth materials for the surface of the cable have been used. To provide for simultaneous release of the connections, the cable housings have been mounted to the bundle in an effort to have them retain their intended routings, and the cables have been cut to appropriate lengths.
Finally, the cargo parachute of the prior art includes a safety cable that prevents the cargo parachute from deploying unless the manual disconnect had been activated. The safety cable has been connected to the manual disconnect handle, and is extracted from a cargo parachute safety loop when the manual disconnect is pulled.